Windows Server Update Services (WSUS), previously known as Software Update Services (SUS), is a computer program developed by Microsoft Corporation that enables administrators to manage the distribution of updates and hotfixes released for Microsoft products to computers in a corporate environment. WSUS downloads these updates from the Microsoft Update website and then distributes them to computers on a network. WSUS is an integral component of Windows Server. The first version of WSUS was know...

@saitobenkei got the point about WSUS, it has plenty more function that bandwidth optimization tool.

Anyway...Into last month the Microsoft strategy about updates changed from single patches to comulative updates, which often are bigger than 100mb.Unfortunately i cannot recall and link a official Microsoft news/statement/notice on Technet about this update policy.